Sound recording and reproducing apparatus



,May 3; 1932; O.LEOPOLD 1,356,344

- SOUND RECORDING AND REPRODUCING APPARATUS Filed April 4, 1951 2Sheets-Sheet 1 I m N JA W May 3, 1932.

o. LEOPOLD SOUND RECORDING AND REPRODUCING APPARATUS 2 Sheets-Sheeib 2Filed April 4, 1951 Patented May 3,

UNITED STATES PATENT orrl'cs OTTO LEOPOLD, OF WEBN'IG'EBODE, HABZ,GERMANY 8 m RECORDING- AND BEPBODUCING AFPABATUS Application filed-April4, 1931, Serial No. 527,716, and in Germany April 8, 1980.

This invention relates to a sound recording and reproducing apparatus,in which the sound conductor is dad in straight direction so thatthetalkmg range of the records is considerably increased .as comparedwith the hitherto used tone arms oscillating in an arc. Moreoverportions of the records can be listened to, so that the stylus can belifted oil the record and then again placed in the same tone oove, fromwhich it has been removed. inc foils, metal foils, celluloid foils andthe like are employed for recording the sound, the st lus standingperpendicularly to the foiL. f it is desired to listen to 16 records ofa difierent kind, the tone conductor is accordingly shifted back withthe parts connected thereto, in order to enable the inclined adjustmentof the stylus in the manner customa therefor.

An em odiment of the invention is illustrated by way of example in theaccompanyin drawings in which:

1 shows an apparatus in top plan view.

Fig. 2 is a front elevation of the apparatus. 86 t Fig. 3 shows a rollerguide in side eleva- Fig. 4 is a side view of the a paratus. Fig. 5 is aside view of the device for lifting the stylus oil? the record. g toFig. 6 illustrates a detail.

A movable tone-arm 2 shifts backwards and forwards in a stationa toneconductor 1. On this arm a short inc ined tone-arm 3 s fitted, whichcarries a sound box 4, which in the case of self recording andreproducing of sounds stands. perpendicularly above the lmagmary lineGextending through the centre of the turn table 5,.(Fig. 1) and isguided straight in the direction of this line. .The shifting of themovable tone-arm 2 in the tone conductor 1 is effected by rollers 7 and8, the roller 8, on which'the tone arm 2 rests, being constructed asshown in Fig. -3. .The -rollers'7 and.8 are mounted in points 9 so thatthey turn easily.

The rollers 7, 8 are carried by bows 10, 10' the inner how 10 beingfixed on the tone conductor 1, whereas the outer bow 10' is fixed on anangle iron 11 fixed by screws to a slot guide 12. A similar slot guide12 is pro vided for the vertical supporting arm 13 of the tone arm(Figs. 1 and 2). The bows 10 and 10 form the bearings for ascrew spindle14, which is driven from a clockwork, electric motor or the like bybevel wheels 31 and 32. The spindle transmission is 1: 2, that isthespindle rotates once, whilst in the same period of time the recordrotates twice on the turn table 5. l

A sleeve-sha ed ring 15 is fixed on the tone arm 2 and a olt, 16 extendstherethrough (Fig. 5), an adjusting nut 17 being screwed on the upperend of this bolt and an eccentric 18 mounted on the lower end of thebolt and bearin against a half nut 19 (Fig. by a b ade s ring 20 (Fig.5) to t e ring 15. When it is esired to record, the eccentric 18 must beso adjusted that the screw threads of the half nut 19 engage in thescrew threads of the spindle 14. The spindle then guides the vertlcaldiamond stylus 21 (Fig. 4) of the sound box 4 on the plate so that thestylus can cut closely juxtaposed spiral grooves into this plate. Duringthe re reduction the half nut is lifted off the spind e (Fig.5)

' Behind the upper guide rollers 7 a shaft y 23 is journaled in twobrackets 22, a-hand lever 24 being fixed to one end of said shaft. Onshort arms 25,extending from the shaft23 a sleeve 26 is mounted whichduring the soun reproduction assumes the position indicated in Fig. 4,bearing on a rearwardly projectin arm 27 of the sleeve 15. When it isdesire to hear a record portion wise, the lever 24 is lowered in thedirection of the arrow shown in Fig. 4, the sleeve 15 thereby movindownwards the arm 27 so that the sound ox 4 is raised to enable thestylus to disengage from the spirals of the record, which continues torotate. If the lever is returned into the posi- 9| tion shown in Fig. 4,the stylus engages exactly at the point at which it was removed. Inorder to prevent an automatic lifting of the sound box, a lockin disc 28is mounted on the shaft '23 with which in the locking position a v5resilient awl 29 engages (Fig. 4) which bgars or; t e locking disc inthe raised position i 5 1 The new device can be employed also for thereproduction of all kinds of records,

which have not been recorded by the owner of the apparatus. conductormust be shifted 15 mms. towards In this instance the tone the rear withthe parts connected thereto, so that the stylus of the sound box can beset at an incline in the usual manner, whereas in the case of selfrecording and reproduction the stylus stands'perpendicular. In bothinstances the line along which the stylus travels must pass through thecentre of the record. In order to effect the shifting the fixing screwsare loosened, with which the parts 11 and 13 are fixed on the carriageguides 12, 12", and the parts 11 and 13 are then shifted 15 mms. so,that the screw holes 30 (Figs. 1 I

and 4) are utilized as fixing points. I "Icla'im: i

1'. In a sound recording andrep'roducing apparatus the combinationcomposed of a stationary tone conductor and a movable tone arm'formingtogether a tone guide, said tone arm shiftable in straight direction insaid tone conductor, an inclined tone arm connected to said movable tonearm,- a sound box carried by said inclined tone arm, rollers mounted inpoints adapted to guide said movable tone arm, a'sleeve fixed on saidmovable tone arm, a bolt extending through said sleeve and said movabletone arm, an adjusting disc on the upper end of said bolt, an eccentricon the lower end of said bolt, a half nut bearing a ainst saideccentric, Ia

blade spring connectmg said half nut to said sleeve, and a screw spindlecontrolling said sound box adapted to engage said half nut during therecording.

2. A sound recording apparatus, comprising in combination a tone guide,a movable 'tone arm of said guide, a shaft behind and above said movabletone arm, a ring-shaped sleeve carried by said arm, a sleeve on saidmovable tone arm, a rearwardly projecting arm of said ring-shaped sleeveadapted to support said sleeve on said shaft, a hand lever on said shaftadapted to rotate said sleeve for lifting the stylus oil the record, ascrew spindle, a half nut resiliently connected to said ring-shapedsleeve adapted to engage said screw spindle and to be disengaged by saidlever, when a record has to be played portion wise, carriage guides, abracket carrying said tone guide shiftable in one of said carriageguldes, and a bracket carrying said movable tone arm, said shaft andsaid screw spindle adapted to be shifted back and fixed in the second ofsaid carriage guides for reproducng records.

In testimony whereof I aflix my signature.

OTTO LEOPQLD.

